Today's network links carry vast amounts of information. High bandwidth applications supported by these network links include, for example, streaming video, streaming audio, and large aggregations of voice traffic. In the future, network bandwidth demands are certain to increase. As a business grows, so can its network, increasing in the number of network elements coupled to the network, the number of network links, and also geographic diversity. Over time, a business' network can include physical locations scattered throughout a city, a state, a country, or the world. Since it can be prohibitively expensive to create a private network that spans these great distances, many businesses opt to rely upon a third-party provider's network to provide connectivity between the disparate geographic sites of the business. In order for the business' network to seamlessly function through the provider network, the provider network must be able to provide a medium for transmission of all the business' various types of datastreams, including multicast transmission.
Since a provider network can support communication from several customers at a time, it is desirable to provide those customers different routing property options in how data may be transmitted across the provider network. Options may be expressed to provide various quality of service (QoS) selections (e.g., faster/more expensive connection, slower/cheaper connection, and redundant connections. It may also be desirable to provide load balancing in the provider network so that certain core routers do not get over loaded with traffic, while others continue to have surplus bandwidth. QoS and load balancing can be performed, for example, by defining various topologies within the provider network.
A transport tree is defined through the provider network to define a path for a customer's data, either unicast or multicast. It is desirable that the definition of the transport tree be responsive to the routing properties required by the customer. In order to enable such responsiveness, routing property identification is interpreted by core routing nodes within the provider network. It is therefore further desirable that a mechanism be provided to supply the core routing nodes in the provider network with identification of the desired routing properties during the building of a transport tree through the provider network.